A conventional portable router is illustrated in FIG. 1. The router has a motor 10 which attaches to the base 11 of the router. A sub base attaches to the plate 14 of the base of the router. A router bit is attached inside the router base 11 and driven by the router motor 10. The handles 12 are attached to the base 11 and allow an operator to guide the router when in operation.
A router is used to cut grooves into wood for ornamental and decorative purposes in such things as cabinets, doors and furniture. When a conventional portable router is used, a tremendous amount of dust and chips are thrown from the router bit through the opening 15 and into the air. The motor 10 pulls air through it for cooling purposes, this air flow further serves to scatter chips and dust around the work area.
The chips thrown from the router bit can be harmful to the operator, causing cuts and scrapes as well as allergic reactions if the operator is allergic to the type of wood being worked. The Occupational Safety and Health Association (OSHA) has very strict guidelines about this type of activity in the work place.
The OSHA regulations for these types of machines can be found in 29 CFR .sctn. 1910.212. Specifically in subsection (a) the regulations provide that:
. . . One or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, . . . flying chips and sparks.
Thus, in the work place it is now very important that a router is guarded to comply with these OSHA regulations.
A router dust guard was presented by E. F. Johnston in U.S. Pat. No. 3,022,806. This router dust guard is designed to fit over a router that is a single component with the motor and bit both housed in the router housing 16. The guard 18 slides over the router housing 16 and is connected to the lower router flange 13. This guard 18 would not work with the conventional router illustrated in FIG. 1 because it is designed to fit over a router housing having a circular housing and thus would not fit over the motor 10 and the handle acceptors. A conventional router allows the operator to adjust the motor up and down depending on the depth of cut desired. The router dust guard as presented by Johnston would not allow the operator to make those adjustments.
A dust removal attachment for a router was presented by Charters in U.S. Pat. No. 4,821,365. This dust removal attachment has a diamond shaped base plate 12 which connects to a mounting flange 32 having a concave body portion 26. The vacuum attachment 20 is positioned over this concave body portion 26 to remove dust and chips. This invention also uses bristles 30 to surround the aperture 14 and the bit.
Pin routers are well known in the art. Built as a stationary machine, a Pin router has a router bit on an extension arm, positioned above a table. The piece of wood to be cut is slid on the table, under the router bit. Instead of the router bit being moved about the wood as in a conventional portable router, when using a pin router the wood is moved by the operator around the router bit to cut the pattern into the wood.
Computer Numerical Controlled (CNC) Routers are also well known in the prior art. CNC routers will automatically cut a preprogrammed ornamental pattern into a piece of wood of a specified size. These CNC routers are big, expensive and can be slow if more than one size of router bit must be used in the pattern. Because of their size the CNC routers are not portable.
Thus, it would be desirable if a router dust hood could be adapted for a conventional portable router which would allow for cooler motor operation and lower wear on the router motor and bit. It would also be desirable if the router dust hood could be used to eliminate extraordinary heat buildup, reduce fire hazards and eliminate operator injury caused by airborne dust and chips.